Summary:Purpose: To evaluate visual outcome and complications after bimanual microincision cataract surgery (MICS) with implantation of an Akreos MI60 intraocular lens (IOL).Material and method: This study comprised 40 eyes of 22 patients after MICS. The IOL was implanted through a 1.9 mm or smaller clear corneal incision. One year after operation, uncorrected and best corrected distance visual acuity, best corrected near visual acuity (logMAR), contrast sensitivities (CS) (CSV-1000), induce astigmatism, complications and patient satisfaction were analyzed.Results: The Akreos lens was implanted through mean incision of 1.8 ± 0.01 mm. One year after surgery the mean uncorrected and the best corrected distance visual acuity (UDVA, BCDVA) and the best corrected near visual acuity (BCNVA) significantly improved (UDVA: preoperatively – 0.7 ± 0.6; postoperatively – 0.04 ± 0.17; p <0.005; BCDVA: preoperatively 0.61 ± 0.6; postoperatively – 0.01 ± 0.12; p< 0.001; BCNVA: preoperatively – 0.56 ± 0.42; postoperatively – 0.0 ± 0; p<0.005). CS in photopic adaptation were within normal age-matched limits. One year after surgery, there was not significant induced astigmatism measured by vector analysis. There were no serious postoperative complications. Visual significant PCO was observed in 1 patient. All the patients were highly satisfied with the quality of the vision.Conclusions: Our results show that MICS with Akreos MI60 lens implantation is a procedure which let receive very good visual function results, fast visual rehabilitation as well as high patients’ satisfaction.

Słowa kluczowe: MICS, Akreos MI60, funkcja wzroku, powikłania.

Keywords: MICS, Akreos MI60, visual function, complications.

Introduction
Microincision cataract surgery(MICS) is defined as an ope­ration performed by
incision less than 2 mm (1).
This minimally invasive technique provides better stabilization of the wound
and faster visual rehabilitation. A significant decrease of eye injury, a
better stabilization of wounds and minimal surgically induced astigmatism, as
well as significant reduction of intra- and postoperative complications are
further advantages of the procedure MICS. Following the “operational trends”, a
number of lenses that can be implanted by an incision of less than 2 mm is
growing up.
The one of this lenses is an Akreos MI60 (Bausch & Lomb). Up to date in the
polish literature there was no study describing visual outcomes in patients
after implantation of this type of lens. That is way, we decided to evaluate
visual outcome and complications one year after bimanual microincision cataract
surgery (MICS) according to Alio and al methods (2-4) with implantation of an
Akreos MI60 intraocular lens (IOL). The MICS procedure has performed in our
clinic since 2005 (5).

Material and methods
The study comprised 40 eyes of 22 patients (10 females, 12 males), with a mean
age of 54.23 ± 23.34 years undergoing cataract surgery (Emery Little
classification: A1-2 , C2-6, H4-5, F3-27 eyes), with binocular implantation of
Akreos MI60 lenses.
Exclusion criteria included other ophthalmic diseases, pseudophakia in one eye,
astigmatism >2.00 D.
Akreos MI60 is an one piece with 4 haptics, aspheric, acrylic-hydrophilic,
containing 26% water lens. It is a bi-convex lens with sharp edges, a diameter
of the optic part and the total diameter are equal 5.5–6.2 mm and 10.5–11 mm,
respectively. The lens can be implanted into the eye by clear corneal incision
with a dia­meter of about 1.8 mm, using the LP 604 350 injector (Fig. 1).
The surgeries were performed by one surgeon (L. W.) in topical anesthesia (Proxymetacaini
hydrochloride – Alcaine). The lens was removed with bimanual technique from
corneal microincisions (mean 1.2 x 1.4 mm) at a distance of 90° from each other.
The anterior chamber was filled with viscoelastic (Discovisc). Circular
capsulorhexis diameter was approximately 5 mm. After hydrodissection,
delineation and fragmentation of nuclei with 2 phacochoppers according to the
method described by Alio et al. (2), the lens was removed by ultrasound
phacoemulsification – low power Fako – mean 9% (Infinity).
After bimanual irrigation and aspiration of cortical masses one of the corneal
incisions was widened to approximately 1.8 mm and through this incision an
Akreos MI60 was implanted.
Target refraction was emetropia, and IOL power calculations were done using IOL
Master (Carl Zeiss-Meditec, Jena, Germany – the software version 2005,
A-constant recommended by the manufacturer with SRK-T formula). Final incision
size after IOL implantation was measure with a special caliper (Asico). After
evacuation of viscoelastic from the anterior chamber, hydration of the wound
edges in order to increase its tightness were performed. After the surgery 3
times a day for 3 weeks an antibiotic and corticosteroid drops were used.
Follow-up examinations were performed by an independent investigator before and
1 year after surgery.
Before and 12 months after surgery the following examinations were performed:
uncorrected and the best corrected distance visual acuities (UDVA, BCDVA), the
best corrected near visual acuity (BCNVA) (EDTRS table). At the end of surgery
final incision size was measured. One year after surgical induced astigmatism (SIA
– vector analysis), the best corrected photopic (85cd/m2) contrast sensitivity
(CS) for distance with and without glare [CSV-1000; 3, 6 12, 18 cycles/degree (cpd)],
postoperative complications, subjective symptoms and patients satisfaction were
analyzed.
Visual acuity, contrast sensitivity results before and 12 months post operation
were compared using the Wilcoxon test. A p value less than 0.05 was considered
as a statistically significant.

Results

Final corneal incision size
Mean of final corneal incision size after implantation of Akreos 60MI was equal
1.80 ± 0.01 mm (range, 1.7 to 1.9 mm). Incision of 1.7 mm was achieved in 3
eyes, 1.8 mm in the next 34 eyes, in 3 eyes was 1.9 mm.

Visual acuity for distance
Mean of UDVA and of BCDVA for distance are shown in Table I.
One year after surgery BCDVA and UDVA were significantly improved in comparison
to preoperative values ​​(p <0.005). One year after surgery 10% of patients
required only slight correction glasses (average + 0.125 D) for 0.0 and better
vision. One year after surgery in 77.5% of patients visual acuity without
correction was 0.1 logMAR and better.

Visual acuity for near
One year after surgery, the mean of the BCNVA was statistically better in
comparison to preoperative values (before surgery – 0.56 ± 0.42; after surgery
– 0.0 ± 0.0; p<0.05).

Refraction
One year after surgery, the mean value of spherical refractive error for
distance was significantly lower (before surgery – 0.52 ± 1.46 D, range from
-4.00 to +2.75; after surgery – 0.16 ± 0.36 D, range from -1.50 to +1.50 D;
p<0.05). The SIA mean one year after surgery was 0.42 D.

Contrast sensitivities
The mean photopic, the best corrected CS for distance with and without glare
were within normal limits in comparison to the normal population between 50 and
75 years old (Fig. 2).

Postoperative complications
No patient had a surgical wound leaks or burns of the cornea. One year after
surgery in 2 eyes significant posterior capsule opacifications were detected
and successful YAG laser treatment was performed.

Patient satisfaction and subjective symptoms
All patients were very satisfied with the quality of vision. None patient had
unwanted effects (glare, halo).

Discussion
The modern technology using ultrasound or laser energy allows the removal of
cataract by an incision of 2.0 mm and less.
There are different types of lenses that can be implanted by corneal
microincision such as Acri.Smart (Zeiss), ThinOptX
UltraChoice 1.0 (ThinOptiX Inc), SuperFlex ( Rayacryl Rayner Intraocular lenses
Ltd) and others (6-8).
In the study group, the lens folding and unfolding in the natural lens capsule
was very fast and under control. There were no cases of lens damage during the
implantation. It should be noted that the implantation of the lens with 1.7–1.8
mm incision was possible without any technical problems.
In our study, the mean corneal incision size, finnaly after implantation Akreos
60MI was consistent with the average published by Alio et al. (1.82 ± 0.16 mm)
(4).
Analysis of the obtained visual acuity results indicated a significant
improvement of uncorrected and the best corrected visual acuity for distance
and the best corrected near vision. One year after surgery, in 80% of eyes UDVA
was equal 0.1 logMAR or better, and significant improvement BCDVA was obtained.
All patients received the BCNVA equal 0.0 logMAR. These very good visual acuity
results for distance and near, even better (Table I) than reported by Alio et
al. (UDVA 0.04 ± 0.17 and 0.32 ± 0.23, BCDVA 0.01 ± 0.12 and 0.08 ± 0.16) (4),
were achieved because a very restrictive inclusion criteria were used.

In our group of patients, vector analysis of the SIA
revealed the value below 0.50 D and confirmed that MICS procedure do not create
significant postoperative astigmatism. Obtained mean SIA (0.42 D) was
consistent with the results described by others performing MICS surgery with
Acri.Smart 48S. Some researchers observed even slightly greater SIA (Alio et
al. 0.50 D and more) (8-10).
No significant decentration, tilt or structural damage of the lens during
implantation pointed to the high quality of the presented IOL model. Sharp
edges of the lens optic and haptic reduced the early incidence of posterior
capsule opacification (PCO). One year after surgery in 20% of eyes not
significant PCO was observed, but only in 5% eyes YAG laser capsulotomy was
necessary. Alio et al. reported in 36% of eyes posterior capsule opacification
in the same observation time. The higher percentage of PCO in Alio study in
comparison with presented study results is probably related with smaller study
group (4,11).
In our study, the results of contrast sensitivity for distance were within
normal limits of healthy people in the same range of age indicated very good
performance of this type of IOL (12). There were no complications during and
after surgery. The patients were highly satisfied with the quality of performed
procedures and implanted lenses due to the fact that they received mostly very
good, uncorrected visual acuity for distance in the absence of subjective
symptoms (glare, halo).
In summary, the results of presented study suggest that MICS with Akreos MI60
lens implantation is a procedure which provide for the patient very good visual
function as well as high patients’ satisfaction. So, we would recommend the
MICS and this type of IOLs for the cataract surgeons and patients.

Financial disclosure: the authors have no financial
interest in any of the methods or products.